ok so this isn't that helpful but i found a css website that gives out simple pieces of the css code to use for profile stuff, i used it myself so here it is : https://www.w3schools.com/css/default.asp
here's the bit i used, incase you don't wanna go to the website itself (though i would recommend it, it seems to be relatively straightforward with teaching about the codes used on here)
background-position: right top;
'background color' can be changed into a color hex code [ex : #ff0000 for red] which you can find by simply searching 'color hex code' on google and choosing a website to use for it.
the url bracket is where you would drag and drop a certain image/gif as your background. i'm sorry if some don't work, it happened to me too :(
next, the white + green glow effect on my text. i used this command for it :
text-shadow: 3px 3px 10px white,
4px 4px 20px #00ff00;
the two first codings that say 'px' are the colours of shadow effect around text, and the third 'px' means how blurry you want that layer of shadow to be. there are 2 lines of the same type of code for this one, as there are 2 layers of colour
the parts that say 'white' and the hex code are custom colours for the glow around the about text, and you can change them however you like!
that's all i have for now, i've never coded before in my life and i sure as hell know i'll never do it again after i finish setting up this profile- to all actual cool coders i wish a thanks simply for existing. idk how y'all do it but like hell am i gonna ask with my short memory lmao